


Before the Fire

by Interverse



Series: Cherryberry - Alternate Timelines [2]
Category: Undertale (Video Game)
Genre: Alternate Universe - Underfell (Undertale), Alternate Universe - Underswap (Undertale), First time... sorta?, Fluff, Fluff and Smut, M/M, Magical skeletons are confusing oof, Smut, Vaginal Sex
Language: English
Status: Completed
Published: 2019-03-02
Updated: 2019-03-02
Packaged: 2019-11-06 09:57:18
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 4,123
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/17937626
Author URL: https://archiveofourown.org/users/Interverse/pseuds/Interverse
Summary: Red took on a little too much at once, attempting to try something new with his boyfriend Blue in a place that doesn't exactly allow for taking your time. Blue brings him home and takes care of him.





	Before the Fire

**Author's Note:**

  * For [Krystal_Twi](https://archiveofourown.org/users/Krystal_Twi/gifts).



> This is a continuation of [Warming Each Other Up](https://archiveofourown.org/works/17917463), [written by Krystal at my request eek], so there will be some plot holes and confusing statements if you haven't read that.

Blue had been aroused, not to the point of his magic forming without intent, but enough for it to be a bit uncomfortable when he was left unattended. But, this was for Red, who was certainly worth the walk back home and much, much more.

 

Their fingers laced together, they started off, and Blue soon noticed a bit of the crimson magic making up his boyfriend's thighs was still peeking out from the bottom of his shorts. “You can dispel your magic,” he said, surprise in his voice.

 

“Nah,” Red huffed, still a bit shaky. “I need to practice this anyhow.”

 

Blue let it go, though he knew that the effort would be draining Red’s energy. He wanted him to be as comfortable as he possibly could. The walk was only about half an hour in reality, but it felt like it took much longer. Blue still felt bad, and he was eager to make up for his oversights. He asked Red if he was okay at least a dozen times on the way, earning a sigh and an affirmative answer each time.

 

Blue fumbled with the keys once he had made it back to his house, fingers numb from the cold. He opened the door for Red once he had managed to get it open, then stepped inside after him and wiggled out of his boots. Red kicked off his own shoes, wandering further into the house and sitting on the couch. Once Blue had hung his jacket up in the closet and slipped his gloves off, the Fell monster spoke up. “So…”

 

Blue turned to face his boyfriend with a reassuring smile, approaching him and kneeling down so they were at eye level. He placed his hands on Red’s summoned thighs through his shorts. “We don’t have to, you know. I don’t want you to be uncomfortable.”

 

Red leaned forward, wrapping his arms around Blue’s neck and pressing a kiss to the corner of his mouth before nuzzling into his neck. “I want to.”

 

Blue breathed in the other monster’s familiar scent. “Okay.”

 

He reluctantly pulled from Red’s embrace, then unfortunately had to venture back outside for what he needed to accomplish. Because of the cold and the fact that heating wasn’t affordable for everyone, Snowdin kept firewood piled high within everyone’s reach, free to take. Blue grabbed an armful of logs, then went back to his house, regretting his decision to take the venture without putting jacket or gloves back on. Red watched as he lit a fire once he was inside, then spread a soft blanket out in front of the weak flames trying to get their bearings.

 

Blue turned to face him with a grin, cheeks heating as the air around him did. “I know it probably won’t be as comfortable as the bed, but I want you to be warm.”

 

Red shrugged. “Fine by me.”

 

He slid from the couch, then scooted over onto the blanket and crossed his legs before looking down into his lap with crimson cheekbones. Blue joined him a moment later, slowly extending a hand and lifting his chin so he was looking at him. “We need a safeword first, remember?”

 

Red nodded, cheeks flushing deeper. “Yeah.”

 

Blue slowly slid his hands under Red’s jacket and eased it off of his shoulders, shuddering at the warmth against his bones. “How about… cold?”

 

Red nodded. “Cold… okay.”

 

Blue leaned forward, letting his mouth hover just above Red’s and murmuring “Say it again, and we’ll stop,” before closing the gap between them.

 

Red whimpered into the kiss, wrapping his arms around Blue’s ribcage and leaning into him. The Swap monster brought one of his hands up to cradle the back of the other skeleton’s skull while he wound the other one around the back of him to gently stroke along one of his floating ribs. Red huffed against him when one of his fingers caught on a scar, and Blue took the opportunity to flick his tongue outwards and into his lover’s mouth.

 

Red welcomed the intrusion, tightening his embrace and groaning lowly when Blue circled his piercing with his tongue. The smaller skeleton went slow, gliding his fingertips over each and every one of Red’s ribs while enjoying every little disgruntled noise he earned in return, and by the time he had begun to caress the other monster’s clavicles, he gently pushed.

 

Red complied, allowing himself to be lowered onto his back with a shaky breath against Blue’s mouth. Blue settled over him, pressing another firm kiss to his love’s mouth before trailing off to the side, showering Red’s cheek and jaw with little pecks and laps. He moved down further, passing his tongue once along Red’s cervical vertebrae before latching on and suckling a little less than gently.

 

Red let out a squeaky little gasp, his arms shooting up and scrabbling for purchase, soon managing to wrap themselves around Blue’s ribcage and dig their claws into his spine. Blue ran his hands down Red’s ribcage until he reached the softness of the summoned abdomen the Fell monster was still sporting, earning a hitch in his boyfriend’s breath. He didn’t bother to do much touching, only shifted down Red’s body and consequently broke away from his neck, then hooked his thumbs under the bottom of his shirt and pulled upwards. Red raised his arms, assisting in the removal of his sweater. Once it was discarded, Blue claimed his companion’s mouth in another kiss, but didn’t linger long before lowering himself again and licking a wet stripe up Red’s sternum. His breath stuttered when he felt the flutter of his counterpart’s Soul against his tongue, a shiver starting down his spine with the pathetic whimper Red let out.

 

He gently nibbled and licked along a few of Red’s ribs, but his patience was wearing thin. He looked up at Red, and once he received a shy nod, moved further down his body and trailed a series of light kisses down his stomach. Red arched his back beneath him, hands falling to his sides and grabbing fistfuls of the blanket. It’s not like they hadn’t done this before, although this time was most certainly different. Plus, Red’s insecurity never faded, no matter what he chose to form with his magic.

 

Another glance up to the monster he loved, another gesture to continue, and Blue slowly eased Red’s shorts down over his hips and legs before tossing them aside. Unsurprisingly, when Blue directed his vision back to the monster beneath him, he found Red’s thighs to be pressed tightly together, a bright blush blazing across his cheeks and nasal ridge. Blue softened his eyelights. Touching was one thing, but seeing was another. It had taken a long time for sex to become part of their relationship at all, and much longer after that still for Red to be comfortable with it in general - especially as a bottom.

 

Blue leaned down, and pressed a gentle kiss to one of Red’s hips, earning a gasp and a small jolt. He kissed the other hip, then looked up at his alternate with love reflected in his eyelights. “It’s okay,” he murmured.

 

Red swallowed loudly, then nodded and relaxed himself. Blue slid his hands between Red’s thighs and pulled them apart ever so slowly. The moment his eyes landed on the bright crimson magic, cast over with the flickering shadows of the flames, he was in love. The lips were full and puffy, splaying outward and practically inviting him in while a delightful little bead of magic was just barely peaking out from underneath his clitoral hood.

 

An indignant huff had his eyes flicking up to the other skeleton’s face, which was flushed even brighter than before. “W-Well?”

 

Blue smiled, leaning to the side and pressing a soft kiss to one of Red’s inner thighs. “You’re _perfect_.”

 

Red lifted one of his arms up and placed it over his face, hiding his eyesockets. “No m’not…”

 

Blue leaned in closer. “Yes you are.” His hot breath blew out over Red’s magic, eliciting a pathetic whine and tremor from the Fell skeleton.

 

Blue kissed the top of his boyfriend’s new configuration of ectoflesh, smiling at the squeaky moan he got just from that alone. He moved down after that, and traced a finger around Red’s outer labia. Red canted his back a bit, so Blue pressed a bit harder and added another finger, massaging the magic in a way that would take the tickle out of the sensation.

 

Red made a choked noise, so Blue stopped and looked up, alarmed. “Red? Are you alright?”

 

“Um… y-yeah,” the other skeleton panted, voice thick. “I’m just… hurry up,” he finished, letting his head fall back down onto the blanket.

 

Blue bit the inside of his cheek. “If you say so.”

 

He shifted his fingers so that they brushed against Red’s lips, and the soft gasp he received in return was indication enough to keep going. He circled Red’s magic a few more times before placing two of his fingers more firmly against the soft magic and spreading it apart. Red whimpered just as Blue gasped when he saw how aroused the larger skeleton was. His entrance was gleaming with shiny fluid, the bright cherry color of it only enhanced with the warm light the fire cast onto it.

 

“Can I-”

 

“Yes,” Red hissed. “Now.”

 

Blue dipped a single finger into the wetness, getting a small breath from Red as he brought it to his mouth and licked the liquid magic from his bones. It tasted strongly of cinnamon, just as the rest of Red’s magic did, and the flavor sent his own magic disobeying and gathering at his pelvis. Blue ignored it, Red’s taste still thick and sticky on his tongue as he went back with two fingers this time, swiped up some of the magic lubricant, then moved them upward and ghosted them just barely over the tip of Red’s clit. The skeleton’s entire body seemed to twitch despite how small of a touch it was, the motion accompanied by a pitiful whine.

 

Blue touched him again, a bit more firmly this time, and got the same reaction, only with more desperation. He had manifested in his pants at that point, cock hard and pressed into the floor, but he wasn’t going to let that distract him when something so much more important was right there in front of him. He dipped his head down and slowly licked along Red’s outer folds, pulling away just before he reached the other monster’s clit.

 

“Y-You can touch it more, you know…” Red breathed shakily, “Just don’t go pinching and shit like you did earlier…”

 

“Okay…”

 

Blue leaned in and plunged his tongue deeper into Red’s folds this time, slowly dragging his magic upwards until it was pressed against his lover’s clit. Red gasped, but seemed alright, so Blue circled the bead of magic with his tongue once and then twice before pulling back at an uncharacteristically loud moan from Red.

 

“N-No,” Red grunted, “Keep… going…”

 

Blue did, latching on to his counterpart’s clit and giving it a single, gentle suck as one of his fingers found his entrance and pushed inside to the first knuckle. Upon receiving no negative reaction, he went in to the second knuckle, and aside from a small whimper, Red was unresponsive, so Blue finally reached the third, breaking away from the other monster’s clit for only a second before pressing his tongue flat against it.

 

Red’s magic tightened around his finger, causing Blue to grunt in surprise with how constricted the passageway already was. “Does that hurt?” he quietly asked after lifting his mouth the just slightest bit from Red’s magic.

 

“N-No,” Red wheezed, “It feels good…” Blue’s eyes widened when the Fell monster’s swollen clit gave a visible twitch. “Please, sweetheart… p-put your mouth back…”

 

Blue did, and the statement proved to be true, because minutes later, when Red was trembling beneath him, he was able to slip a second in and only receive a broken moan from his boyfriend. He flicked his tongue back and forth on Red’s clit, gentler than he probably would have liked if he was in the other monster’s position, but still enough to have the Fell skeleton shivering and whining pitifully. Blue perked up when the amazing sounds morphed into words.

 

“F-Fuck, Blue, oh god- _fuck_ \- I’m- I’m-”

 

The words were lost again in a series of shrill gasps, and just as Red’s walls began to flutter around his fingers, he stopped them in their slow, shallow thrusting and instead curled them upwards, massaging into a spot he knew he certainly enjoyed with as much gentleness as he could manage.

 

Red grew quiet, the only sound to escape his mouth when he convulsed and spasmed around Blue’s fingers sounding akin to a suffocated choke. Blue moaned into his magic, cock throbbing and leaking in his pants while he wiggled his fingers just the slightest bit, luckily breaking Red’s stretch of voicelessness when unusually high whines and moans spilled out from between his sharp teeth, not subsiding until he had gone limp and his climax had tapered off. Blue pulled back, sucking in a breath and licking over his teeth, breaking all the viscous ropes that Red’s juices had formed while letting himself shudder at the sweet and yet fiery flavor before slowly extracting his fingers with a wet squelch. Red let out a final, defeated moan, and after a few moments of deep breaths, managed to lift his head and look at Blue.

 

“Hey,” Blue said gently, a bit out of breath himself, both from his previously restricted breathing and his own desires growing more and more urgent by the moment.

 

“H-Hey…”

 

Blue crawled up to Red’s face, then leaned down and pressed a kiss to his nasal ridge. “Was that good?”

 

Red nodded shyly, weakly reaching up to grip Blue by the cheekbones and pull him down for a proper kiss. When they parted, Red turned his head to the side and attempted one of the sly expressions Blue had come to know well, to a limited degree of success. “Guess you thought it was good too.”

 

Blue’s cheeks warmed, but he pushed through his flusterment and answered honestly, running a loving hand over the top of Red’s skull. “Yes, I did. I said you were perfect, didn’t I?”

 

Red brushed the comment aside with an embarrassed mumble, and when Blue only smiled at him, he furrowed his browbones. “Well, what’s the holdup?”

 

“Huh?”

 

“Aren’t you going to fuck me?”

 

Blue wanted to, _very_ badly, but Red had proved how sensitive he was, and he didn’t want to overwhelm him this first time. “Maybe we should wait a li-”

 

But Red was having none of it, quickly snorting out his rebuttal. “If you think I’m getting off this blanket without your cum inside me, you’re wrong.”

 

Blue made a face somewhere between embarrassed and disapproving at the crudeness of the statement, but he gathered himself and moved himself back down between his partner’s legs again. “Okay, if you really want.”

 

Red flashed him one of his adorable lopsided grins. “You’d better believe I do, Baby-Blue.”

 

He smiled at the affectionate nickname. “But I’m going slow,” he added, doing his best to make his tone serious. “Okay?”

 

“Whatever, sure, fine.” Red’s expression was losing its casualness, creases appearing between his browbones.

 

Blue brought a hand up to his mouth, licked over his index and middle fingers, then brought them back down to Red’s magic and slowly pushed them inside. He got a strained grunt from the other skeleton, but protests were soon to follow.

 

“B-Blue, last time I checked, this isn’t what is usually being referenced when someone asks to be ‘fucked’.”

 

“I know,” Blue sighed, bashfully glancing up at his lover. “But you’re kinda…”

 

“...Tight?”

 

“Uh, yeah, that…” The term had always seemed uncomfortably lewd to Blue, but he had yet to think of a better alternative. “I just want to make sure I don’t hurt you.”

 

He wasn’t huge or anything, but he wasn’t taking any chances. He wiggled his fingers within his companion’s magic, seeing how much give it had. Red’s inner walls were still gripping him rather snugly, but Blue didn’t think he had reached the monster’s limit just yet. He maneuvered a third finger to Red’s entrance, and gave a little prod to test it. He hesitated, but after a moment, pushed. It was a strain at first, but once he had gotten the tip in, the rest was quite easy, the slickness of Red's magic and relative smallness of Blue's fingers no doubt being of help.

 

Red whined, and Blue looked up, alarmed. “A-Am I hurting you?!”

 

“No,” the Fell skeleton panted, shifting a bit. “Just… can ya… put less things in me?”

 

“...What?”

 

“Can you ditch the fingers and use your cock?”

 

Blue shot the other a look, but he really didn’t think it would be of good health to his pants if he burdened them with any more stray drops of precum. “Fine,” he breathed, “Just one more thing.”

 

He scooted backwards, then dipped his head down between Red’s thighs again, softly lapping at his magic. Red gasped, and Blue grunted into his pussy, nuzzling deeper until his tongue entered the Fell skeleton and his nasal ridge pressed against his clit.

 

Red was plenty wet already, but again, Blue wasn’t taking any chances. Plus, the familiar tang of his lover’s magic had dulled in his mouth, and he was happy for an excuse to indulge again. But, with a particularly desperate groan from Red, Blue gave in to his own impatience, shifting his head to the side and taking one of Red’s soft, plump lips in his mouth before slowly pulling away until the magic could be extended no further, slipping from his mouth and returning to its original position.

 

Red only laid there and whimpered pathetically as Blue rose to his knees and untied his bandana. He pulled his shirt over his head after that, and after a moment of deliberation, struggled with his pants until they had joined the rest of the discarded garments in their haphazard pile on the floor. Red’s attention was all his again once Blue was gripping onto his thighs with his femurs pressing into the warm ectoflesh of the larger monster’s thighs. Blue let out a shaky breath as he wrapped a hand around his aching, neglected magic and aligned it with Red’s before glancing up at him.

 

He didn’t even get a change to ask for approval before Red was nodding vigorously, attempting to jerk his hips upwards enough to have their magic touch, but failing and just sinking back into the blanket with a defeated whine. Blue let out a shaky breath, lowering himself and parting his alternate’s labia with the head of his cock. With how warm and slick Red was, combined with his existing tendency to be a bit noisy - not to mention how long he had been left unattended - even that was enough to have Blue panting out a little moan. Red followed in his footsteps, crimson eyelights flicking in order to meet Blue’s, making the sheer amount of want in them painfully prominent.

 

Blue was convinced enough. He aligned himself with Red’s entrance after hastily rubbing against the Fell skeleton’s clit a couple of times, and pushed. Just like last time, it was a bit of a struggle at first, but once the head was inside, Blue was able to slowly ease himself forward into the wet warmth with little to no difficulty. Once seated all the way inside, he simply allowed a shiver to pass through his body, letting his mouth part to let his ragged breaths free more easily. This may have been Red’s first time with a pussy, but this was a new experience for Blue too, considering that he’d been a virgin before Red came along.

 

While it felt he was floating numbly in the sensations for minutes, it probably wasn’t even half a second before he was pulled back to reality by a contraction around his cock from the magic enveloping it and a gasping moan from the monster it belonged to. Blue’s hesitation came back in full. “R-Red?! Are you okay? Am I hurting you??”

 

“N-Nah,” Red huffed, though his expression looked like it was locked in that of a wince. “I mean, just… g-give it a second…”

 

Blue was ready to bail right then and there, and honestly wanted to. He couldn’t stand the pained expression overtaking the face of the monster he loved, but he listened, and over time, it lessened. After a while, Red let out a long breath, deflating against the blanket and loosening around Blue’s length. “Okay… you can… move…” he breathed.

 

Blue swallowed, twitching within the soft confines of the other monster’s magic. “Al… alright…”

 

Blue gripped onto one of Red’s thighs, then raised his free hand and slowly swiped his thumb over his clit. Red sucked in a shaky breath, and Blue took this opportunity to slowly ease himself out of the warmth of his magic. He held back his own noises in favor of listening to Red’s with more clarity, the suction trying to keep him inside more intense than he had expected it to be. He rubbed slow, gentle circles into Red’s clit upon sinking back inside, and Red expressed his appreciation with a keening whine, quite unusual given the usual gravely quality to his voice.

 

Blue was sick of this. He lowered himself down over the other monster until their sternums collided, wrapping his arms around Red’s ribcage and covering his clavicle in kisses. The Fell monster’s hands came up to rest on his back, signaling his shared happiness with the closeness. Blue took his time with his thrusts, waiting in between each of them until Red had further loosened around him before finding his rhythm, albeit a slow one.

 

Red’s ragged, uneven breaths blew warm and fast against the top of his skull, sending tingles down his spine and making the already overwhelming sensations all the more present. The novelty of the surely unnecessary amount of moisture and the unevenness of the velvety walls holding him so tightly were bordering on breathtaking. Blue clumsily reached down with a hand and found Red’s clit, tenderly massaging at its hood before pulling it back and earning a loud, broken moan from his lover with the more direct touches.

 

“B-B-Blue,” Red whimpered, “Can ya… _a-ah_ \- speed things up a bit?”

 

Blue was conflicted with a moment of doubt at breaking his promise of slowness, but upon registering just how pleading his companion’s voice had sounded, he broke. He was still going slow, all things considered, but it was plenty fast enough to have Red shuddering beneath him and practically sobbing out his moans, apparently too far gone to speak.

 

Fortunately, Blue knew from his own experience of being on Red’s current side of things that he was close. The constricting tightness of before was back in full, but he could feel small pulses coming from the magic around him. This was not at all an issue, because the deep ache in Blue’s own magic and pelvis was nearly unbearable and he knew that as soon as Red climaxed, he would be gone as well.

 

Blue panted heavily into the crook of Red’s neck, taking the risk of rubbing at his clit a little more vigorously in his own desperation. His decision paid off, Red going rigid just a few seconds later and choking on his moans. Blue removed his fingers from Red’s clit, knowing that its sensitivity would have skyrocketed, and that this effect would have applied tenfold with how sensitive his Fell counterpart already was.

 

Blue held on to the monster he loved for dear life, gasping when Red’s magic clamped down on him, released him, then gripped back on twice as hard. Blue didn’t waste time with extra movement, barely managing to hilt himself again before he was tipped over the edge, shivering and releasing rope after rope of his ectoplasm deep within Red’s hold. This sent his lover squirming, digging his claws so hard into Blue’s spine that it could have pierced ectoflesh if it were there.

 

Blue didn’t mind. He only cared about the monster right there beneath him, beautiful and perfect and squeezing him so damn _tight_ \- Even after both of their orgasms had settled and Blue was left with nothing but a pleasant tingle in his bones, he had no desire to move or speak. This feeling of being loved, and satisfied, and safe… it was all he needed, there before the fire.

**Author's Note:**

> Caring Blue is just... mmmhmhmhmh. Good. Very good.


End file.
